[meteorite-list] Shallow Groundwater Reservoirs May Have Been Common on Mars

[Ron Baalke]

NEWS RELEASE FROM THE PLANETARY SCIENCE INSTITUTE

SENT: 
Nov. 22, 2010

FROM: 
Alan Fischer
Public Information Office
Planetary Science Institute
520-622-6300
520-885-5648
fischer at psi.edu

Shallow Groundwater Reservoirs May Have Been Common on Mars

An international research team led by the Planetary Science 
Institute has found evidence for reservoirs of liquid water 
on Mars at shallow crustal depths of as little as tens of meters. 

J. Alexis Palmero Rodriguez, research scientist at PSI, and the 
research team came to this conclusion after studying collapsed 
terrains that occur within some of the solar system's largest 
channels.

Investigations of similar but vastly larger zones of collapse 
located where these channels initiate have led previous 
investigations to postulate that the upper crust of Mars 
contained vast aquifer systems concealed underneath a global 
frozen layer kilometers in thickness. However, these zones of 
large-scale collapse are rare on Mars and their formation most 
likely took place under exceptional hydrogeologic conditions. 
The PSI-led team's work documents the distribution of groundwater 
within crustal zones located beyond these regions.  

Citing geologic evidence found in the planet's largest system of 
channels located in southern circum-Chryse and results from 
thermal numerical modeling, Rodriguez and his co-authors propose 
in an article published in Icarus that groundwater reservoirs 
may have been common within the Martian upper crust.

The numerical model implies that where fine-grained, 
unconsolidated sedimentary deposits existed on top of an icy 
permafrost layer, melting of ground ice and the development of 
subsurface aquifers could have taken place at shallow depths.  
Extrapolations of their results to the present Martian conditions 
imply that groundwater may currently exist underneath thermally 
insulating fine-grained sedimentary deposits approximately 120 
meters in thickness. Thus, despite large differences in 
hydrogeologic histories, average surface temperatures, and 
internal heat flows of Earth and Mars, some areas of Mars might 
be similar to typical permafrost on Earth, where shallow aquifers 
are confined by thin layers of icy permafrost.
   
These reservoirs could mean the presence of accessible water near 
the Martian surface, Rodriguez said, which could greatly reduce 
the costs of future manned exploration of the planet. In addition, 
it could mean habitable environments may exist at shallow depths, 
he said.

This research was funded by a grant to PSI from the NASA Mars 
Data Analysis Program.

Rodriguez is lead author on the paper. Co-authors are: Jeffrey 
S. Kargel, Department of Hydrology & Water Resources, University 
of Arizona; Kenneth L. Tanaka, Astrogeology Science Center, U.S. 
Geological Survey; David A. Crown, Planetary Science Institute; 
Daniel C. Berman, Planetary Science Institute; Alberto G. Fairén, 
SETI Institute and Space Science and Astrobiology Division, NASA 
Ames Research Center; Victor R. Baker, Department of Hydrology & 
Water Resources, University of Arizona; Roberto Furfaro, Department 
of Aerospace & Mechanical Engineering, University of Arizona; Pat 
Candelaria, Department of Aerospace and Mechanical Engineering, 
University of Arizona and Sho Sasaki, National Astronomical 
Observatory of Japan.

CONTACT:
J. Alexis Palmero Rodriguez
Research Scientist 
Planetary Science Institute                
520-622-6300 
alexis at psi.edu
 
 
PSI INFORMATION:
Mark V. Sykes
Director
520-622-6300
sykes at psi.edu

PSI HOMEPAGE:
http://www.psi.edu